Since the advent of orbiting spacecraft that operates in a zero gravity ("g") environment there has existed a need to separate gas from liquid and particularly where the liquid is water. As is well known in this field of technology, the development of water/gas separators has been substantially successful, in fact, some units have evidenced success rates that have removed 100% of the gas from the treated water. Of course, it is abundantly important that the water which may be used in a pumping system and the like is free from air bubbles.
Typically, these prior art separators utilize a rotating drum to separate and collect the liquid and use a pitot tube to remove the collected liquid from the drum. Other types of separators use rotating paddles and coalescers instead of the rotary drum. The paddles serve to maintain a swirling mass of liquid inside of a circular housing manifesting the separation of the liquid/gas interface in a zero "g" or variable "g'" environment. The coalescer is typically fabricated from a wire mesh which is porous to the flowing air/water stream and serves to coalesce the minute water droplets into larger water drops so as to be in a form that is readily collectable. Coalescer material is disclosed, for example, in U.S. Pat. No. 3,339,349 granted to R. F. Farnum on Aug. 28, 1964 which patent is commonly assigned to United Technologies Corporation and incorporated herein by reference.
While the later described liquid/water separator has been extremely efficacious and has exhibited no carry over in the gas vent stream when operating on clean, non-soapy water, it has proven less than efficacious when soap or the like is contained in the liquid being treated. In fact in actual tests of the water/gas separator of the type using paddles, the soap allowed the formation of fine bubbles in the liquid as the paddles rotate the water ring inside the fixed housing. This resulted in carry over in the water in the form of fine bubbles. Additionally, foam formed in the air at the center of the separator adversely affected the coalescer function and in fact, defeated it. Because this occurs at the spinning screen of the coalescer adjacent the rotating axis, the gas vent evidenced the formation of foam. The carry over in the water in the form of fine bubbles and in the gas vent in the form of foam are entirely unacceptable conditions.
We have found that we can obviate the problems enumerated in the above paragraphs by providing an improved coalescer, eliminating the paddles, utilizing other means for rotating the water ring inside the fixed housing, improved venting and controlling means.